If there is already a thread about this topic, I couldn't find it and I need help...I have made a cake covered in Royal Icing Flowers and need to know if it will cause them to break apart if I put the cake in the refrigerator. The cake is frosted with Cup A Dee Cake Butter Cream, which at room temperature is very soft and fluffy, but I need the frosting firm in order to transport it.

Moisture will break down the RI. When your cake comes to room temperature, condensation can form on the surface of the cake which can melt RI. If you can box the cake and wrap the box, the condensation will form on the wrap when the cake is removed from the refrigerator.

Also, remember that the moisture in the frosting can soften the RI where it comes in contact, even at room temperature.

Can you not hold off placing the flowers until you take the cake from the fridge and let it come to room temp?
You will still have to place some kind of barrier between the RI decos and the BC (fats are death to RI)
What were you planning on using for glue?

There are several posts by WMI TexasSugar about piping RI directly on Crisco-coated waxed paper and Crisco-coated fondant cakes... here's one:
http://cakecentral.com/modules.php?name=Forums&file=viewtopic&t=731105&highlight=crisco

So, the grease-free utensils rule applies when mixing RI, yet you can pipe RI on shortening/fat.